In 1993, the long-awaited results of the Diabetes Control and Complications Trial (DCCT) were announced. The study monitored blood sugar control for up to nine years in 1,441 people with Type 1 diabetes who were between the ages of 13 and 39 when they entered the study. Researchers used periodic measurements of glycosylated hemoglobin (HbAlc) to evaluate overall control. HbAlc test results indicate average blood sugar control during the preceding two to three months.
The DCCT conclusively proved that in people with Type 1 diabetes, degree of blood sugar control is directly related to the risk of developing diabetic complications or experiencing progression of existing complications. Keeping blood glucose levels near the nondiabetic range reduced the risk of developing retinopathy by 76%, the risk of progression of existing retinopathy by 51%, and the risk of needing surgery to treat retinopathy by 50%. It also reduced the risk of early kidney damage by 42%, the risk of more severe kidney damage by 51%, and the risk of neuropathy by 60%.
Based on the study results, the researchers recommended that most people with diabetes strive to maintain blood sugar levels as close to the nondiabetic range as possible. They cautioned, however, that the closer to normal one keeps blood sugar levels, the greater the risk of severe hypoglycemia (low blood sugar). The researchers also cautioned that the results might not apply to some groups, such as children, since they were not included in the study.
Shortly after the DCCT reported its results, the American Diabetes Association (ADA) published a series of treatment goals for blood sugar control based on those results. (The recommendations are summarized in "ADA Guidelines for Blood Sugar Control" on page 97.)
These treatment goals are widely used today by adults with diabetes. However, it remains unclear whether they should also be used by children with diabetes. This subject is hotly debated among pediatric diabetes specialists. Some experts say that treatment goals for children should be the same as those for adults, while others recommend less aggressive goals, such as HbAlc levels greater than 8% or 9%.
Why is there such a difference of opinion among the experts? To answer this important question, we need to consider the pros and cons of achieving near-normal blood glucose levels in anyone with diabetes and specifically in children.
With only 5 to 25 milligrams sodium per serving. (The exception is fresh spinach, which is naturally higher in sodium at 65 to 160 milligrams per serving). But adding salad dressing, bacon bits, cheese, and other ingredients found in salad kits can boost the sodium content to as much as 500 milligrams per serving. To keep the sodium content of a salad low, use less dressing and limit or avoid adding bacon bits, cheese, and olives. Carbohydrate. Lettuces and most greens are considered "free" foods in a diabetes meal plan because they have 5 or fewer grams of carbohydrate per serving. Most bagged salads that contain just greens also have less than 5 grams of carbohydrate per serving, as stated on the label. The exception is spinach, which averages about 10 grams per serving, but 5 of those 10 grams come from fiber, which is not digested or absorbed by the body.
When dressing, croutons, and other ingredients are added in the salad kits, the carbohydrate grams increase accordingly. Check the label for total grams of carbohydrate, and if you use carbohydrate counting as your meal planning method, count one-half carbohydrate choice for a serving of salad that provides 6 to 10 grams of carbohydrate, and one carbohydrate choice for a serving that contains 11 to 20 grams of carbohydrate. Fiber. Contrary to popular belief, lettuce is not the greatest source of "roughage," or fiber, in our diet. One serving of most bagged salads or greens provides only 1 or 2 grams of fiber. Spinach takes the lead in fiber, with an average of 4-5 grams per serving. If you want to increase the fiber content of your salad, try adding other vegetables like carrots or shredded cabbaged, fruits, or kidney or garbanzo beans. Protein. Salads are not a significant source of protein, providing a few grams at most per serving. If your salad is your whole meal, you may want to add some ingredients that are high in protein, such as meat, poultry, fish, cheese or other dairy products, nuts, or grains such as bulgur or quinoa. Protein sources are not usually included in complete salad kits.
Hypoglycemia-blood sugar lower than 60 mg/dl-is a potentially serious, acute complication of diabetes. Anyone who takes insulin is at risk of developing it. Hypoglycemia impairs mental function and-if blood sugar sinks low enough-can lead to coma and even death. The dangers of hypoglycemia are heightened if a person is involved in an activity, such as driving a car or riding a bicycle, during which mental impairment could cause a crash or an injury.
Studies in young children, particularly children whose diabetes was diagnosed before age five, have uncovered another possible danger of hypoglycemia. These children have a slightly increased incidence of learning disabilities later in childhood. It has been suggested that these developmental problems, which are generally quite mild and do not occur in all children diagnosed at an early age, may be the result of repeated episodes of hypoglycemia. There is some evidence from animal studies that young brains may be particularly susceptible to damage from hypoglycemia. So one argument for maintaining higher blood sugar levels in children is to avoid hypoglycemia and the risk of developing brain damage.
Do the preteen years count?
Chronic complications of the eyes, kidneys, and nerves rarely, if ever, occur before the onset of puberty (about age 11 in girls and age 12 in boys), regardless of blood sugar control during the childhood years. It has been argued that because complications do not occur until puberty, there's no reason to maintain blood sugar levels as close to normal as possible during childhood and increase a child's risk of serious episodes of hypoglycemia.
However, recent investigations have demonstrated that the development of diabetic eye and kidney diseases is related to both level of blood sugar control during childhood and total duration of diabetes, not just duration after puberty. Thus, the "clock" for the development of diabetic complications begins ticking at diagnosis, and lower blood sugar levels during childhood can reduce the risk of developing complications later in life.
Developing a plan
So how do children with diabetes and their families figure out what to do? There are no easy answers, and each family and its health-care providers must examine these issues and decide on their own course of action. I will share my approach with you, although I do not have a secret formula for success.
I do not believe that hypoglycemia is more or less dangerous for children with diabetes than for adults. For example, driving a car during an episode of hypoglycemia is no more dangerous than having an episode of hypoglycemia while playing on the school playground, where a fall could result in an injury. I do believe, however, that every effort should be made to minimize the risk of hypoglycemia in children, particularly very young ones who cannot verbalize how they feel.
The aim of blood sugar control is to achieve blood sugar levels similar to levels in a person without diabetes: A person who doesn't have diabetes has an average HbAlc level of less than 6%. There's no single correct way to maintain near normal blood sugar levels, nor is there any guarantee that a person who follows his diabetes care plan "perfectly" will always have blood sugar levels in the desired range. For this reason, the terms "good control" and "bad control" should be avoided, because they imply a link between a person's behavior and his blood sugar control, which is not necessarily the case.
In seeking realistic goals for blood sugar control in children, the ADA guidelines are an excellent place to start. Goals must be individualized, though, because every child is different. For example, during the "honeymoon" phase, early in the course of childhood diabetes, insulin requirements are low, and the risk of hypoglycemia is low. At that time, it's realistic to shoot for HbAlc levels less than 7%.
After the honeymoon phase, insulin requirements increase, and risk of hypoglycemia is higher. Many children are not able to maintain HbAlc levels less than 7% during this time, so for them, keeping HbAlc levels below 8% is an appropriate goal. For most children with diabetes, this degree of blood sugar control will achieve the right balance between the ideal goal of normal blood sugar levels and the realities of day-to-day life with diabetes, including the risk of hypoglycemia.
What if a child with diabetes can readily maintain HbAlc levels in the 5%-7% range without many episodes of hypoglycemia? I would not attempt to "loosen" the blood sugar control to raise the HbAlc level. I would, however, frequently review the child's management plan and discuss ways to minimize the risk of hypoglycemia since, over time, maintaining a low HbAlc level may become more difficult, and hypoglycemia may become more of a problem.
If HbAlc levels are consistently above 8%, a change should be made to the diabetes care plan, whether or not the child has frequent episodes of hypoglycemia. This situation is difficult and requires a meeting between the child's family and his health-care providers to figure out which parts of the treatment plan are working and which are not. Perhaps the treatment plan is a good one but is not being followed exactly. Or perhaps the plan is not working and needs to be altered. For example, switching from Regular insulin to lispro (brand name Humalog), changing the injection schedule, or working out a new meal plan might make all the difference. The best solution to the problem will be different for each child and his family.
For many years at the University af Missouri Children's Hospital Diabetes Program, we have tracked HbAIo levels in the children we see. We have found a steady fall in the average HbAIc level, beginning about the time the DCCT results were announced in 1993 and continuing until the present. The average HbAIc level of all our patients under 18 fell from about 8.5% to %.%%. We have not noted any increase in the frequency of hypoglycemia. I believe (but cannot prove) that the lower blood glucose levels are mostly related to having specific blood sugar control goals based on DCCT results.
Tips for preventing hypoglycemia
There are a few steps you can take with your child to help prevent hypoglycemia without giving up blood glucose levels near the normal range. I will pass along the excellent recommendations of Dr. Julio Santiago, a noted diabetes specialist from Washington University in St. Louis, who passed away in 1997. Hypoglycemia frequently occurs during the night, when it may go unnoticed. This is a serious problem, because if hypoglycemia is not noticed and treated right away, blood glucose can continue to drop. To prevent nighttime hypoglycemia, Dr. Santiago recommended the following:
||Check your child's blood sugar level at bedtime (or have him do it). He should eat a snack if the result is below 120 mg/dl (or the level specified by his doctor).
||Nighttime hypoglycemia should be suspected if morning blood
for blood sugar
The American Diabetes Association suggests target ranges for blood glucose control, which appear below. These are only guidelines, however. Everyone needs individualized goals for blood glucose control, so your child's target range may be different from the ones given here. The blood glucose goals are listed for whole blood readings and for the equivalent plasma readings. All home meters test whole blood, but some give a reading in plasma values.
|Blood Glucose Goals
|Antes de acostarse
||less than 7%
Additional action recommended: if higher than 8%
sugar levels are frequently below 80 mg/dl.
||Regimens that give high insulin levels overnight should be avoided. For example, large doses of intermediate-acting insulin (such as NPH and Lente) should not be given at supper, and large doses of short-acting insulin should not be given at bedtime.
||Glucagon should be available in the home of every child with diabetes, and its proper use should be well understood by family members and other caregivers.
Other diabetes experts suggest doing a blood glucose check in the middle of the night (at 3 AM) once a week to monitor for nighttime hypoglycemia. Monitoring at 3 AM is also recommended if a child was more active than usual during the day, hasn't eaten well, or had low blood sugar at bedtime.
A few products on the market may help prevent hypoglycemia during the night. Special snack bars that contain "resistant starch," which is broken down slowly and absorbed slowly from the digestive tract, have been shown to lower the risk of nighttime low blood sugar.
Other products in development, such as continuous blood glucose monitoring devices, are
just beginning to become available. They promise more effective protection against hypoglycemia in the future, but we won't know how well they work until people have a lot more experience with them. In the meantime, there's no substitute for regular blood glucose monitoring.
|Hard work pays off
We know much more about the management of childhood diabetes today than we did before the results of DCCT were announced. However, treatment remains a constant challenge for children with diabetes, their families, and their health-care providers. Achieving the proper balance between the best possible blood sugar control and the risk of hypoglycemia requires hard work, and it's a team effort. Now that the DCCT results are in, families can put in the work knowing that their efforts will pay off.